This invention relates to an improvement in phenolate reactants used in making polyarylene polyethers by condensation reactions. This invention also relates to the use of these phenolate reactants in manufacture of halogen-terminated polyarylene polyethers with a low, but select, degree of polymerization and in conversion of such halogen-terminated polyarylene polyethers to polyarylene polyethers having terminal amine functionality. This invention still further relates to a method that enables production of these polyarylene polyethers with greatly improved reliability and desirable correspondence between weight average and number average molecular weights.